1. Field of the Invention (Technical Field)
The present invention relates generally to the field of wastewater treatment and, more specifically, to the reduction in the level of nitrogen- and phosphorous-containing compounds and organic compounds in wastewater released into the environment.
2. Background Art
Toilet and kitchen waste is the primary source of nitrogen, phosphorous, and the bulk of solids in most domestic wastewater discharges. These toilet and kitchen waste discharges can be segregated from the wastewater discharged from other plumbing fixtures (e.g., powder room wash basin) using separate sewer plumbing, and captured in a separate non-discharging tank for storage, treatment, and disposal as a method for nitrogen, phosphorous and/or solids reduction. Cluster systems and large community systems can use centralized, segregated treatment and disposal systems for toilet and kitchen waste with non-toilet waste remaining on the individual lot or on separate plots for treatment and disposal.
Wastewater containing nitrogen compounds and phosphorous compounds such as ammonia, organic nitrogen, nitrates, nitrites, and phosphates that contaminate ground and surface water resources is a major concern in a world facing potable water shortages. Traditional onsite wastewater systems including septic systems do little or nothing to reduce the level of nitrogen and phosphorous compounds in the released wastewater. No low-cost technology is available to remove nitrates (NO3), nitrites (NO2), and phosphates (PO4) from wastewater. Release of these compounds to environmental surface water, or especially ground water, is to be avoided.
Background art in the field of wastewater treatment is limited to treating the entire volume of wastewater with traditional bacterial digestion, oxidation, settling, and disinfection (usually using chlorination). More advanced methods, such as ozone and ultraviolet radiation, also are used to treat water and wastewater. There does not appear to be any prior art in which segregation, separate handling, solids reduction, and treatment of wastewater containing high levels of nitrogen waste leading to a zero-effluent system is applied other than having toilet waste segregated and held in a holding tank which is pumped periodically or used in composting systems.
Ultraviolet (UV) radiation can be used as the sole agent to sterilize liquids. Several disclosures relate to the development of devices and configurations for using UV to sterilized liquids. For example, U.S. Pat. No. 3,971,947 issued to Lambert, et al. and entitled “Ultraviolet water purifier”, describes a method and apparatus for the generic use of UV radiation to sterilize water. U.S. Pat. No. 4,017,734 issued to Ross, and entitled “Water purification system utilizing ultraviolet radiation”, describes the use of linear configurations using UV radiation to sterilize water. U.S. Pat. No. 4,101,777 issued to Reid, and entitled “Fluid purification device and ultraviolet lamp therefor”, describes the use of yet another configuration to use UV radiation to sterilize water. U.S. Pat. No. 4,141,686 issued to Lewis, and entitled “Disposable liquid sterilizer unit”, describes the use of disposable devices that use UV radiation to sterilize water. U.S. Pat. No. 4,255,663 issued to Lewis, and entitled “Disposable liquid sterilizer unit”, describes the use of still another disposable configuration that uses UV radiation to sterilize water. U.S. Pat. No. 4,372,860 issued to Kass, entitled “Method and an apparatus for cleaning water in a swimming pool”, describes the use of specific configurations for UV radiation sterilization of swimming pool water. U.S. Pat. No. 4,400,270 to Hillman, entitled “Ultraviolet apparatus for disinfection and sterilization of fluids”, describes sterilization of water by UV radiation. U.S. Pat. No. 4,766,321 issued to Lew, et al. and entitled “Symbiotic filter-sterilizer”, describes the use of configurations that use UV radiation to clean filters.
Further, U.S. Pat. No. 4,892,712 issued to Robertson, et al. and entitled “Fluid purification”, describes the use of specific configurations requiring various catalysts and UV radiation to sterilize and clean water. U.S. Pat. No. 4,959,142 issued to Dempo, and entitled “Water treating apparatus”, describes the use of specific configurations that use UV radiation to sterilize constantly flowing water. U.S. Pat. No. 5,120,450 issued to Stanley, and entitled “Ultraviolet radiation/oxidant fluid decontamination apparatus”, describes the use of a non-stick coating on the outside of lamp sleeves in configurations that use UV radiation to sterilize water. U.S. Pat. No. 6,221,259 issued to Kittrekk, and entitled “Process and catalyst for photocatalytic conversion of contaminants”, describes the use of specific catalysts in certain configurations that use UV radiation to sterilize and clean water. The disclosures of each these references are herein incorporated by reference.
Additionally, it is known to use of ozone alone to sterilize water and/or treat the organic content water. For example, U.S. Pat. No. 4,007,120 issued to Bowen, and entitled “Oxidation and ozonation chamber”, describes the use of ozone to treat and disinfect water. U.S. Pat. No. 4,053,399 issued to Donnelly, et al. and entitled “Method and system for waste treatment”, describes the use of ozone to oxidize and disinfect wastewater. U.S. Pat. No. 4,176,061 issued to Stopka, and entitled “Apparatus and method for treatment of fluid with ozone”, describes the use of ozone in the form of micro-bubbles to oxidize and to disinfect wastewater. U.S. Pat. No. 4,255,257 issued to Greiner, et al. and entitled “Process for the treatment of water”, describes the use of pressurized ozone to treat water. U.S. Pat. No. 4,545,716 issued to Boeve, and entitled “Method of producing ultrapure, pyrogen-free water”, describes the use of highly-concentrated, substantially-pure ozone to treat deionized water. U.S. Pat. No. 4,572,821 issued to Brodard, et al. and entitled “Apparatus for dissolving ozone in a fluid”, describes the use of pressurized ozone to treat water. U.S. Pat. No. 5,130,032 issued to Sartori, and entitled “Method for treating a liquid medium”, describes the use of ultrasound to disperse ozone in water and the use of ultrasound to aid in the cleanup of ozonated water. U.S. Pat. No. 5,207,993 issued to Burris, and entitled “Batch liquid purifier”, describes the use of ozone in water with recirculation of the water through the ozone injection region to purify water. U.S. Pat. No. 5,868,945 issued to Morrow, et al. and entitled “Process of treating produced water with ozone”, describes the use of ozone to treat water, containing hydrocarbons, at elevated temperatures. U.S. Pat. No. 6,006,387 issued to Cooper, et al. and entitled “Cold water ozone disinfection”, describes the use of ozone dissolved in water to disinfect mechanical assemblies. U.S. Pat. No. 6,115,862 issued to Cooper, et al. and entitled “Cold water ozone disinfection”, describes the use of ozone dissolved in water to disinfect mechanical assemblies. The disclosures of each these references are herein incorporated by reference to the extent that they are not inconsistent with this application.
There also are disclosures relating to the use of oxidation, singly, to treat wastewater or water. For example, U.S. Pat. No. 3,992,295 issued to Box Jr., et al. and entitled “Polluted water purification”, describes a process of catalyzed oxidation. U.S. Pat. No. 4,141,829 issued to Thiel, et al. and entitled “Process for wet oxidation of organic substances”, describes a process of oxidation occurring at elevated temperatures. U.S. Pat. No. 4,604,215 issued to McCorquodale, and entitled “Wet oxidation”, describes a process of oxidation occurring at elevated temperatures. U.S. Pat. No. 4,699,720 issued to Harada, et al. and entitled “Process for treating waste water by wet oxidations”, describes a process of oxidation using catalysts. U.S. Pat. No. 4,793,919 issued to McCorquodale, and entitled “Wet oxidation system”, describes a process of oxidation occurring with mixing or stirring of the fluid. U.S. Pat. No. 5,053,142 issued to Sorensen, et al. and entitled “Method for treating polluted material”, describes a process of oxidation occurring in a fluid. U.S. Pat. No. 5,057,220 issued to Harada, et al. and entitled “Process for treating waste water”, describes a process of oxidation using catalysts. U.S. Pat. No. 5,145,587 issued to Ishii, et al. and entitled “Method for treatment of waste water”, describes a process of oxidation at elevated temperatures. U.S. Pat. No. 5,158,689 issued to Ishii, et al. and entitled “Method for purification of waste water”, describes a process of oxidation at elevated temperatures.
Additionally, U.S. Pat. No. 5,370,801 issued to Sorensen, et al. and entitled “Method for treating polluted material”, describes a process of oxidation occurring in a fluid. U.S. Pat. No. 5,614,087 issued to Le, and entitled “Wet oxidation system”, describes a process of oxidation occurring in a stirred or mixed fluid. U.S. Pat. No. 5,807,484 issued to Couture, et al. and entitled “Waste water treatment”, describes a process of oxidation using trickle filters. U.S. Pat. No. 5,888,389 issued to Griffith, et al. and entitled “Apparatus for oxidizing undigested wastewater sludges”, describes a process of supercritical oxidation occurring in a fluid at elevated temperatures and pressures.
A further reference useful as background to the present invention is Brandes, M. “Characteristics of Effluents from Separate Septic Tanks Treating Grey and Black Waters From the Same House”, J. Water Pollut. Control Fed., 50 pp. 2547-2559, 1978.